This document shows two ways to measure current with an analog input for voltage.
Current Measurement with Shunt Resistor
Current Measurement with Hall-Effect-Based Current Sensor IC
Resistance: 0.1 Ohm Load Capacity: 10 W
Measured Voltage: 0.5 V
R = U / I
I = U / R I = 0.5 V / 0.1 Ohm I = 5 A
Maximum current for Load Capacity 10 W:
P = I² * R
I = sqrt (P / R)
Imax = sqrt (10 W / 0.1 Ohm)
Imax = 10 A
There are different Hall-Effect-Based Current ICs. This example shows a ACS712 from Allegro MicroSystems, Inc.
You can order the IC with breakout module or you can build your own board. In ACS712 datasheet is a circuit diagram. Search in web for ACS712 datasheet. AC712 deliver not the best results if you want to measure only some milliampere.
ACS712 consists of a linear Hall circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field which the Hall IC converts into a proportional voltage.
This picture shows the ACS712ELCTR-20A-T with breakout module. ACS712ELCTR-20A-T has an optimized Range of +/- 20 A and a sensitivity of 100 mV/A.
Please note that there are different Hall-Effect-Based Current ICs with different ranges and sensitivities.
The LabVIEW code for the Hall-Effect-Based Current measurement is the same like for Shunt Resistor. The scaling depends on the Hall-Effect Sensor type.